The U.S. unveiled new restrictions on China’s access to vital components for chips and AI, escalating a campaign to contain Beijing’s technological ambitions but stopping short of earlier proposals that would have sanctioned more key Chinese firms.

The Department of Commerce slapped fresh curbs on the sale of high-bandwidth memory chips made by U.S. and foreign companies, likely affecting South Korea’s SK Hynix and Samsung Electronics as well as Idaho-based Micron Technology. Those components handle data storage and are essential for AI applications.

The agency also expanded existing controls on chipmaking gear, including products made by U.S. firms at foreign facilities, but with carve-outs for key allies, such as Japan and the Netherlands. That comes after months of negotiations between Washington, Tokyo and the Hague, during which Biden officials floated — but ultimately did not pursue — applying U.S. controls to companies like Tokyo Electron and ASML Holding.